# Urgent help calculator problem

• Nov 26th 2007, 06:38 AM
mojo6592
Urgent help calculator problem
Well heres an example of what is happening (i'm not too good at laying out my maths):

Its cos
Hyp = 10

Cos x = 4 ÷ 10
X= cos(-1) 0.4
The answer should be 66.4 but on my casio casio s-v.p.a.m it says 0.99997563
what am i doing wrong?

heres a link to the calculator if it helps
http://www.sprinterservis.cz/darky/i...ator_casio.jpg
• Nov 26th 2007, 08:43 AM
Soroban
Hello, mojo6592!

Hard to understand what you're saying . . . but I'll take a guess.

Quote:

$\cos x \:=\:0,4$

Then: . $x \:=\:\cos^{-1}(0.4)$

This is correct!
[You're pressing the wrong keys on your calculator.]

You should get: . $x \;=\;\cos^{-1}(0.4) \:=\: 66.42182152^o \;\approx\;66.4^o$

Press: . $\boxed{2^{nd}}\;\boxed{\text{cos}}\;\boxed{0.4}\;\ boxed{=}$

That is, use the "key" that has: . $\boxed{\cos^{-1}}$

What you found is: . $\boxed{\cos}\:\boxed{0.4} \:=\:0.999975631$

• Nov 26th 2007, 09:08 AM
janvdl
Quote:

Originally Posted by mojo6592
Well heres an example of what is happening (i'm not too good at laying out my maths):

Its cos
$\boxed{Shift}$ (The button at the top left) $\ \boxed{cos} \ \boxed{0,4} \ \boxed{=}$